Laboratory rodents such as rats and mice are widely used for preclinical animal testing. In operations or experiments using such rodents, a respiratory tube is inserted into the respiratory tract, and a ventilator is connected to the respiratory tube for control breathing and anesthesia.
Mice are exemplary small rodents used for animal testing, and the weight of mice is about 20 g to about 30 g, and the diameter of the respiratory tract of mice is very narrow in the range of 1 mm to 1.5 mm. A tube may be inserted into the respiratory tract of a rodent while looking at the larynx and vocal cord of the rodent using a laryngoscope. However, since the diameter of the respiratory tract of rodents is too small to see, it is difficult for inexperienced experimenters to insert a tube into the respiratory tract of a rodent. In addition, if a rodent is not anesthetized nor in a stable anesthesia state, it is more difficult to insert a tube into the respiratory tract of the rodent because the rodent moves.